Africa dwarfs Chad: about 30,370,000 km² km² against 1,270,927 km² km². At true size Africa is about 23.9× larger — the whole of Chad fits into Africa roughly 23 times.
The old Mercator map treated both about equally (1× vs 1.1× inflation), so at least their relative sizes were preserved — even if both were drawn at the wrong absolute scale.
Chad fits 23× into Africa.